The thread topic concerns wristlocks being effective in an alive setting.

Getting back to the OP, I'd say it depends on whether the lock is applied from a standing position, or from one on the ground. I have safely used wristlocks in sparring on the ground. It should be noted that I was also in fully in control of the other person's core when I did so.

Sparring with wristlocks from a standing position has a higher risk of injury in my opinion. However, depending on the skill of the two partners and the level of contact present, they can still be trained in alive setting. Assuming both people have a good working knowledge of how to use them and the restraint to employ them with an eye toward safety (no cranking, no high speed escape attempts when it's being applied) it can be done.

I used a wrist lock today in practice. In fact, my go-to of late is just to wrist lock off of arm bar defense. I get the tap faster than working to break the grip and having to actually lean back. I can't find a video of this. Another move I need to film I guess.

Fredson Paixao is known as the "king of wrist locks" in BJJ and even won some major tournament with one. Roy Dean also has a wrist lock instructional, so it would be interesting on how he approaches them.

When you have full control over your opponent you can do them safely (slow and controlled) and if they don't work they will usually open up something else. The spots I go for them are off an armbar break, gift wrap or the side control one that Python posted. However, I have yet to catch a guy above purple belt level.

My concern with wrist locks is that when you try to apply them to someone who is pretty skilled you have to either have complete control of them which is hard to achieve on a skilled non-gassed opponent or snap them on really fast which is a recipe for injury.

So I rarely get them outside of the occasional beginner because I'm wary of hurting training partners. In competition it's fair game I guess but kind of a dick move to snap them on.

I highly recommend this thread on a very similar topic. I'm amazed at the degree of wrongness and ignorance several of my posts exhibit, but I still think this one is valid.

Wristlocks in motion while standing are an entirely different beast from wristlocks while the rest of the body is controlled via other means. In other words, a wristlock from a failed jujigatame or sankaku is not even in the same ballpark as a kotegaeshi. I think this is similar to Petter's excellent point about where the control originates.

I think wristlocks when it comes to the clinch and weapons work is an entirely different beast as well.

What a disgrace it is for a man to grow old without ever seeing the beauty and strength of which his body is capable. -Xenophon's Socrates